What does FTP stand for? In computing, FTP stands for File Transfer Protocol, an agreed method for one computer to send files to another over a network. A person or program logs in to an FTP server, then uploads or downloads files, much like dragging items between folders.
FTP is one of the oldest ways to move data on the internet. It predates the web itself, and it is still used to update websites, share large files inside companies and send data between business systems. Two other meanings are common enough to know: functional threshold power in cycling and failure to pay on tax letters.
Quick facts
Stands for
File Transfer ProtocolOther meanings
Functional threshold power (cycling), failure to pay (taxes)Type
InitialismHow to say it
"F T P," one letter at a timeDefault port
21 for commands; 20 for data in active modeSecure versions
SFTP and FTPSStarted
First described in 1971, current standard from 1985
What does FTP stand for, piece by piece?
FTP stands for File Transfer Protocol, and each word names part of the job.
- File: the thing being moved, from a photo to a huge data export.
- Transfer: sending it from one machine to another.
- Protocol: the agreed rules both machines follow, such as how to log in, list folders and start a download.
FTP sits in the same family as HTTP, the protocol behind web pages, and both run on top of TCP. The difference is focus. HTTP mainly delivers pages to browsers, while FTP was built to manage files on a remote computer: upload, download, rename, delete and create folders.
How an FTP session works
- A program called an FTP client connects to the server, usually on port 21.
- The user signs in with a name and password, or as "anonymous" on public file servers.
- The client sends commands to list folders or request a file.
- The files themselves travel over a second, separate connection.
That second connection is why you may see the terms active mode and passive mode. In passive mode the client opens both connections, which works better through home routers and firewalls, so most clients use it by default.
Web host welcome email: "FTP host: ftp.example.net, port 21. Use your account name and password." This tells you where your client should connect to upload the files for your site.
Why plain FTP is being replaced
Classic FTP sends everything, including the password, as readable text. Anyone watching the network between you and the server could see it. Two safer options fill the same role:
| Name | Full form | How it protects data |
|---|---|---|
| FTP | File Transfer Protocol | No encryption |
| FTPS | FTP Secure (FTP over TLS) | Adds encryption to normal FTP |
| SFTP | SSH File Transfer Protocol | A different protocol that runs inside an encrypted SSH session, usually on port 22 |
Most major web browsers have also dropped built in support for ftp:// links, so you now need a dedicated client or a file manager that supports the protocol. Many teams that still say "FTP the files over" are really using SFTP behind the scenes.
FTP outside computing
The letters show up in two other places often enough to cause confusion.
- Cycling and fitness: functional threshold power is the highest average power a rider can hold for about an hour, measured in watts. Training plans set workout zones as a percentage of FTP. "My FTP went up after the winter block" means the rider got stronger.
- Taxes: on tax notices, FTP can mean failure to pay, a penalty for paying a balance late. It is separate from the failure to file penalty.
Writing FTP in a sentence
Use capitals and no periods. Since the letter F is spoken "eff," writers put an in front: "an FTP server." In tech talk FTP also works as a verb.
- "Can you FTP the export to the vendor tonight?"
- "Our backup runs over SFTP, not plain FTP."
- "The FTP login failed because the password changed."
- "Her FTP is about 250 watts."
For more network terms such as IP and DNS, browse our tech acronyms list.
Questions people ask
What is FTP used for today?
It is still used to upload website files, send large batches of data between companies and manage files on remote servers. Many of these jobs now use SFTP or FTPS, the encrypted versions.
Is FTP secure?
Plain FTP is not, because it sends passwords and data without encryption. FTPS and SFTP add protection and are the better choice for anything private.
What is the difference between FTP and SFTP?
FTP is the original protocol and sends data in the open. SFTP is a separate protocol that runs inside an encrypted SSH connection, usually on port 22, and it does the same file jobs safely.
What does FTP stand for in cycling?
It means functional threshold power. It is the average power, in watts, a rider can sustain for roughly an hour, and it is used to set training zones.
Do people say FTP as a word?
No. Everyone reads out the three letters, so it is technically an initialism. In casual talk plenty of people call it an acronym anyway, which nobody minds.